Little is known about plastic changes occurring in the brains of patients with severe disorders of consciousness (DOCs) caused by acute brain injuries at rest and during rehabilitative treatment. Brain-derived neurotrophic factor (BDNF) is a neurotrophin involved in neurogenesis and synaptic plasticity whose production is powerfully modulated by physical exercise. In this study, we compared serum BDNF levels in 18 patients with unresponsive wakefulness syndrome (UWS) and in a minimally conscious state (MCS) with those in 16 sex- and age-matched healthy controls. In 12 patients, serum BDNF levels before and after verticalization with ErigoPro robot-assisted lower-limb training were compared. Serum BDNF levels were significantly lower in patients (median, 1141 pg/ml; 25^th and 75^th percentiles, 1016 and 1704 pg/ml) than in controls (median, 2450 pg/ml; 25^th and 75^th percentiles, 2100 and 2875 pg/ml; ). BDNF levels measured before and after verticalization with robot-assisted lower-limb training did not change (). Moreover, BDNF levels did not differ between patients with UWS and MCS (), or between patients with traumatic and nontraumatic brain injuries (). BDNF level correlated positively with the time since brain injury (). In conclusion, serum BDNF levels are reduced in patients with UWS and MCS and cannot be improved by verticalization associated with passive lower-limb training. Additional studies are needed to better understand the mechanisms underlying BDNF reduction in patients with DOCs and to determine the best rehabilitative strategies to promote restorative plastic changes in these patients.

中文翻译：

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意识障碍患者的血清BDNF水平降低，并且在机器人辅助下肢训练中无法通过垂直化进行调整。

对于由静息和康复治疗期间急性脑损伤引起的严重意识障碍（DOC）的患者的大脑中发生的塑性变化知之甚少。脑源性神经营养因子（BDNF）是一种神经营养蛋白，参与神经发生和突触可塑性，其产生受到体育锻炼的强烈调节。在这项研究中，我们比较了18名无反应性清醒综合征（UWS）和最低意识状态（MCS）患者与16名性别和年龄相匹配的健康对照者的血清BDNF水平。在12例患者中，比较了用ErigoPro机器人辅助下肢训练进行垂直治疗前后的血清BDNF水平。患者的血清BDNF水平显着降低（中位数为1141 pg / ml；^第25和^第75^位百分，1016和1704微克/毫升）比对照（中位数，2450微克/毫升; 25^个和75^个百分位数，2100和2875微克/毫升;）。机器人辅助下肢训练在垂直化前后测量的BDNF水平没有变化（）。此外，UWS和MCS患者之间的BDNF水平没有差异（），或在患有外伤性和非创伤性脑损伤的患者之间（）。BDNF水平与脑损伤后的时间呈正相关（）。总之，UWS和MCS患者的血清BDNF水平降低，而被动下肢训练相关的垂直化不能提高血清BDNF水平。需要进行其他研究以更好地了解DOC患者BDNF降低的基本机制，并确定促进这些患者恢复性塑性改变的最佳修复策略。